Belt sanding machine



May 20, 1953 G. DE. MAMBRo ErAL A 2,835,083

BELT SANDING MACHINE Filed sept. '12', 1955 2 Sheets-Sheet l mm mm l 1NVENT0R$ GENE DEMAMBRO LlNsLv G. BR wN TORNE Y May 20, 1958 G. DE MAMBRO ErAL 2,835,083

BELT SANQING MACHINE Filed sept. 182, 1955 2 sheets-sheet 2 I1 iN IN V EN TORS GENE DEMAMBRO LINSLY G. BROWN TORNE Y United States Patent() BELT SANDIN G MACHINE Gene De Mambro and Linsly G. Brown, Jamestown, N. Y., assignors to The Carborundum Company, Niagara Falls, Y., a corporation of Delaware Application September 12, 1955, Serial No. 533,652 6 claims. (ci. 51-141) This invention relates to belt sanding machines. It is particularly directed to such machines which are designed for sanding wood although they may be employed for sanding other materials.

`One object of the invention is to provide a belt sanding machine so constructed that sanding may be done on both sides of the long stretches of the belt between the pulleys which carry it. Another object of the invention is to provide a belt sanding m-achine with work tables along ythe long stretches of the belt which are s-o constructed that the table or tables may be tilted without movement of the top line of the inner side of the table adjacent the abrasive belt. Another object of the invention is to provide such a machine wherein the abrasive belt is supported throughout the long stretches by a serrated contact or supporting belt. Another object of the invention is to provide such a machine wherein sanding can be done at one end of the machine where the abrasive belt passes over a serrated -contact wheel. Other objects of the invention will be apparent from the description which follows:

The invention has been illustrated with drawings where- 1n:

Figure 1 is a plan View of one embodiment of the invention;

Figure 2 is a front elevation of the same embodiment of the invention;

`Figure 3 is a section along the line 3 3 of Figure 1;

yFigure 4 is a front elevation of one end of the machine illustrating a second embodiment of the invention; and

Figure 5 is a perspective view of a carrier belt adapted for use 'in the machine.

Referring now to the drawings, the machine comprises a base having a front face 1 and a back face 2 reinforced by ribs 3 extending `within the cavity provided by the two faces and by I-beam 53.

Suitably mounted on one end of the base is an electric motor 4 for driving the belts. The upper end of the motor carries a drive pulley 5 about which the carrier belt 6 and the abrasive 'belt 7 travel. The carrier belt travels around a second or idler pulley S and the abrasive belt extends to and travels around a third pulley y9 which is desirably serrated to provide a contact whee The carrier belt 6 is backed up by platens 51 and 52.

Suitably attached to the faces 1 and 2 of the base are table supports 10 which are vertically adjustable by rotation of screws 11 in bearings 12 which are attached to the faces of the base. The rotation of the screws 11 is efr'ectuat-ed by movement of the hand wheel 13. The vertical movement of the supports is guided by pins 14 extending through bearings 15 which are attache-d to the faces of the ibase.

Attached to the under side of the side work tables 16 are elements 17 provided with arcuate slots 18 for tilting the side work tables. Elements 17 are supported by rollf ICC H wheels 20 which lock the elements 17 in ythe desired position.

An important feature of the invention resides in the lfact: that the slots 18 are described as arcs about the upper and inner sides 21 of the side work tables 16. Consequently, when the tables 16 are tilted the line extending along the upper and inner edge 21 of the work table does not move and the inner end of the work table is therefore at a lixed position with respect to the abrasive belt 7 regardless of the extent yto which the work table-s 16 are tilted.

A second feature of the invention is the provision of an idler pulley 8 for the carrier belt 6 which is at least as large in diameter, and preferably of the same diameter as the drive pulley 5. The pulley 8 is mounted on spindle 22 riding in suitable bearings in supporting element 23 which in turn is attached to the base by a bracket 24 provided with pin 25 which forms an axis about which the spindle for the pulley may be tilted. Adjustment of the inclination of the vertical axis of the pulley 8 is made by movement of the screw 26 in the threaded bearing 27 by turning t-he hand wheel 28. When the pulley has been properly positioned it may be locked in place by turning the hand nut 29 which bears on the pin 26 and prevent-s rotation thereof. Adjustment of the inclination of the spindle Z2 is necessary in order to provide proper tracking of the supporting or carrier belt 6.

Tensioning of the carrier belt 6 is provided by moving the bracket 24 in a horizontal plane by revolution of the screw 30 in the threaded bearing 31 which is fastened to a sliding plate on gibbed dovetailed ways, fastened to the base plate. The rotation of the screw is effected by turning the hand wheel 32 which cau-ses rotation of the screw 30 through bevel gears not shown in the drawings.

Tihe third pulley or contact wheel 9 is mounted on sealed ball bearings on a spindle 33 positioned in a suitable bushing attached to a pivot mounted on a dovetailed slide on the base. The spindle 'with its pulley or contact wheel i-s therefore removable by simply lifting the assembly of spindle and contact wheel as a unit out of the bushing. This feature makes it possible to change contact wheels and thus substitute wheels of different diameters by merely lifting out the assembly and replacing it with another having a wheel of the desired diameter. Adjustment of the position of the spindle 33 along a horizontal line to tensi-on the belt is made 'by rotating the screw 34 by turning hand wheel 35. Screw 34 is suitably carried within slide element 36 mounted on the vertical base plate.

Tracking of the abrasive belt is effected by changing the vertical position of the spindle 33 by rotation of the screw 37 brought about by turning hand knob 38, in a manner similar to that described with respect to the idler pulley S.

A third or end work table 39 may be provided for sanding at the end of the machine where the abrasive belt 'travels about the contact wheel 9. In the embodiment illustrated in Figures l and 2 the table 39 is shown as being fixed in position. This table may also be made both adjustable lin a vertical plane and ltiltable by suitable means as illustrated in Figure 4 wherein the support 40 for the table is adjustable vertically by rotation of the hand wheel 41 which results in raising or lowering the table by movement along conventional gibs. Tilting of the Itable is eiected in the manner described with respect to the other tables by loosening `the locking nut 42 which fastens the table in position as it is tilted by movement through the slot 43 as in the case of the side tables.

The end table is also tiltable without movement of the upper and inner edge 44 of the table by reason of the fact that the slot 43 is described as an arc about this upper inner edge 44 as a center. In the embodiment illustrated in Figure-4 the belt is tensioned by rotating the, handV wheel. 45, which causes, movement in. a hori.- zontal plane of the pivoted bracket 46 for the contact wheel spindle 33.

Stillianother :feature of the. invention .is the employ.-v ment of the carrier belt 6 a small portion of which is. shown.in.perspective. in.Fig-ure 5. The. belthas a backing .4'7-,` whichis desirably of a strong cloth su'ch.as wovenV duck, towhich is cemented a rubber or synthetic rubber portionhaving ridges148 and, depressions 49. Neoprene'v has been found to be suitable for this. rubber-like layer.

Sincethecar-riery belt `travels about. theA pulleys 5- and. 8.;

whereas thev abrasive belt stretchesover the carriervbelt and, around.- pulley Sbut continues over around contactl wheel 9, the relative position of the abrasive. belt .with respect to. the. carrier belt is constantly changing. This assists in removingdetritusfrom the belt andlisimportant becauselofthefact that the belt-is usedatthree different stations and. consequently gets very severe treatment.

Machines constructed in accordance with this invenf.

tion have a great. advantage over the machines of the` prior. art. By making pulleys 5` and 8 of substantially the samediameter for carrying the carrier or supporting belt 6 it is. possibletouse both of the long stretches of the abrasive. belt. where the. carrier belt supports. it and by extending the abrasive belt around the contact whee19 and` making thatV pulley or contact wheel of smaller diameter than theA other two, or pair ofpulleys, it is possible to-provide a third work station. Consequently, a very considerableamount of work can be doneonthis one machine simultaneously. In actualuse it has been shown that.I the output of a machine made in accordance with this. invention is several times that of machines heretofore employed.

Whilewe haveshown the machine with two-sidework tables both of which are-adjustable both vertically and angularly it is of coursewithin the purview of the invention toprovidethis feature with respect to only one-of these. side belts, theother being xed in instancesl where the. work is of such character that itr is unnecessary to -tiltorvertically adjust-the table.

Similarly, we have shown theend work table39'- as being leither fixed in position or adjustable bothvertically and angularly. It is olf Icourse feasible to'have this table either xed or. adjustable vertically only'.V One important advantage of the vertical adjustmenty comes from the` fact that it is possibleto use the full width ofv a wide abrasive beltA even though the work is comparatively narrow. When such material is being workedany or--allof'the Itables may be lowered to employ only the lower part of the belt andV as that part becomes dulled the tables may be adjusted vertically so that the work will be applied at fresh surfaces of the abrasive belt.

While we. have illustrated our invention by reference to certain drawings and have described certainconstructionsit is to be understood that the invention is not to be limited tothe specific structures and embodiments illustrated and described herein but rather is to be vconsidered of` the scope of the appended claims.

Weclaim:

1. A belt sander comprising a base, a pairor' spindles mounted onsaid base, a pair of pulleys mounted on said spindles, respectively, for rotation about their longitudinal axes, said longitudinal axes lying in one plane, means for rotating one of jsaid pulleys, an endless-backup belt mounted to travel around said pulleys, said pulleys having substantially identical diameters whereby the two reaches of said backup belt are in parallelism, athird spindle supported from said base remote from said pair of spindles, a third pulley` mounted on said thirdspiudle for` rotation about its longitudinal axis, the longitudinal axis of said thirdlpulley lying in said oneplane, aneendless abrasive belt mounted to travel about one ofsaid pair of` pulleys in superposed engagement with said backup belt and aboutsaid third pulley, saidthird pulley having a diameter smaller than that of said pair of pulleys, whereby said abrasive belt is in continuoussupen. posed engagement with said backup belt along both reaches of said back-up belt between said pair of pulleys, means for inclining the axis of one pulley of said pair in said plane and independent means for inclining the axis of said third pulley in said plane to control tracking of the backup belt and of the abrasive belt respectively, means for moving one pulley of said pair and independent means for moving said third pulley toward and away `from said remaining pulley respectively, to adjust the tension on the backup belt and on the abrasive belt respectively, andl work tables mounted on said base on each side thereof adjacent the two reaches of said abrasive belt and between said pair of pulleys.

2.' A belt sander as in claim 1 including a pair of parallel platens mounted on said base and disposed, respectively, along and between the reaches of the backup beltl to llimit the movement of each reach of said backup belt-andfto supporty said backup belt.

3. A belt` sander as in claim l wherein said endless back-up belt has a serrated surface disposed to engage against the confronting surface of the abrasive belt.

4. A-belt sander as in claim 1 wherein said third pulley is secured/toV said third spindle, and the assembly ofl said third? spindle and third pulley is removable from said-base as a unit.

5. A beltsander comprising a base, a pair o-f spindles mounted onsaid'base, a pair ofpulleys mounted on said spindles, respectively, for rotation about their longitudinall axes, said longitudinal axes lying in one plane, means. forrotating one of said pulleys, an endless backup beltrmountedl to travel around said pulleys, a third spindle supported from said base remote from said pair of spindles, a third pulley mounted on said third spindle for-rotation-about its longitudinal axis, the longitudinal axis of saidthird pulley lying in said one plane, an endless abrasive belt mounted to travel about one of said" pair of pulleys in superposed engagement with said backup belt and about said third pulley, the diameterv of the pulley in said pair that is in intermediate'position between saidthird-pulley and the other pulley of' said pair being at least as great as the diameter of said third pulley whereby said abrasive belt is maintained in continuous superposed engagement with said backup belt along bothreachesof said backup belt between said pair. of` pulleys, means for inclining the axis of one pulleyof; said pair in said plane and independent `means for inclining the axis of said third pulley in said'plane lto control tracking of the backup belt and of the abrasive belt: respectively, means for moving one pulley of said pair andzindependent means for moving said thirdl pulley towardand away from said remaining pulley to adjust the tension on the backup belt andv on the abrasive belt, respectively, andwork tables mounted on said base ou each sidethereof adjacent the two reaches of said abrasive belt between said .pair of pulleys.

6. A belt sander as in lclaim 5 and including: support members. for said work tables mountedY on said base, said members. being formed with arcuate slots that-are formed about, acenter along the top inside edge of the associated work table, roller pins dependent from said worktables ,and disposed to slide in said slots, and means to ,secure saidtables in any adjusted, inclined position.

ReferencesCited in the lile of this patent UNITED STATESPATENTS 

